Labour and delivery: Montevideo units: practice question

A OBG question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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OBG · Labour and delivery: Montevideo units

Sample item

Montevideo units are used to measure uterine activity in labour. How are they calculated, and what total is generally considered adequate?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Sum of the peak pressure above baseline of each contraction in 10 minutes; above 200

Montevideo units are obtained from an intrauterine pressure catheter by adding the amplitudes (peak minus baseline in mmHg) of all contractions in 10 minutes. A total of 200 or more is adequate for labour to progress. It is used to decide whether oxytocin augmentation has failed.

Option by option

  • A. Peak pressure of a single contraction; above 50 mmHg

    A single peak pressure does not give a measure of overall uterine activity.

  • B. Resting uterine tone multiplied by frequency over 30 minutes; above 50

    Resting tone times frequency is not how the units are calculated.

  • C. Sum of the peak pressure above baseline of each contraction in 10 minutes; above 200 (correct)

    Correct. The sum of the contraction amplitudes over 10 minutes is the measure, with at least 200 adequate.

  • D. Number of contractions in one hour multiplied by their duration; above 100

    Counting contractions per hour times duration is not the definition of Montevideo units.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this OBG question

What is the answer to this OBG question?

The best answer is C, Sum of the peak pressure above baseline of each contraction in 10 minutes; above 200. Montevideo units are obtained from an intrauterine pressure catheter by adding the amplitudes (peak minus baseline in mmHg) of all contractions in 10 minutes.

Why is "Peak pressure of a single contraction; above 50 mmHg" not the answer?

A single peak pressure does not give a measure of overall uterine activity.

Why is "Resting uterine tone multiplied by frequency over 30 minutes; above 50" not the answer?

Resting tone times frequency is not how the units are calculated.

Why is "Number of contractions in one hour multiplied by their duration; abov…" not the answer?

Counting contractions per hour times duration is not the definition of Montevideo units.

What concept does this question test?

It tests Labour and delivery: Montevideo units in OBG. A total of 200 or more is adequate for labour to progress. It is used to decide whether oxytocin augmentation has failed.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Labour and delivery: Montevideo units?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.